Silicate Paints - Basics

2023 Author : Hannah Pearcy | [email protected] . Last modified: 2023-11-26 11:39

In principle, silicate paints can be divided into two groups according to DIN 18 363, Section 2.4.1:

1. Two-component silicate paints (2K, also called pure silicate paints) made from potash water glass, pigments and fillers. They do not contain any organic components.
2. Dispersion silicate paints made of potash water glass, pigments, fillers, plastic dispersion, and if necessary, water repellents. The total content of organic components must not exceed 5 percent.

This is the box title

• Basics
• Properties of silicate paints
• Processing of silicate paints
• Double silicification with silicate paints

2K silicate colors

Two-component silicate paints have been used to coat mineral substrates for around 120 years. They consist of the binder potassium water glass (potassium silicate) as well as mineral, alkali-stable pigments and fillers. They are open-pore coatings with high permeability for water, water vapor and carbon dioxide.

Silicate paints harden through silicification. In this process, the water-soluble potash water glass, which is also known as a fixative, creates a water and acid-resistant, glass-like binder. Due to its chemical relationship, potash water glass reacts preferentially with silicate ingredients of the color, in particular with quartz flour, which is also contained in the Histolith silicate colors. Furthermore, the connection to the silicate substrate takes place during the silicification.

The two components - pigments (+ fillers) and fixative - must be mixed in a specified ratio before processing. This mixture is not stable in storage. Once mixed, the craftsman has to process the paint within the time period specified by the manufacturer.

The mixing process must be carried out with particular care, otherwise the quality of the paint will suffer. The 2K silicate paint system Histolith Kristallin from Caparol largely excludes mixing errors. The color component is already pasted in water. The dye powder does not sink in - and with it the associated dust development (health protection). Mixing the pigment paste with the Histolith Fixativ binder component is particularly easy and safe to use.

Dispersion silicate paints

The first dispersion silicate paints came onto the market in the 1980s. They are easier to process compared to purely mineral silicate paints. Since they also adhere to non-mineral substrates, they are also more versatile.

Histolith facade paints based on dispersion silicate are highly permeable to water vapor and additionally water-repellent. They therefore have very good building physics properties and optimally protect the subsurface from building moisture.

The good durability is based on the so-called double silicification: the binder potassium water glass reacts both with special reactive fillers and with the mineral substrate.

The interior silicate colors Histolith Bio-Innensilikat and Histolith Raumquarz are highly diffusive and absorbent. This is an advantage especially when used on interior walls with condensation. The wall surface remains dry, which reduces the accumulation of dirt particles and the fogging effect.

Silica sol silicate paints

Kieselsol silicate paints are further developments of the dispersion silicate paints. They contain potash water glass and silica sol as a binder as well as an organic content of up to 5 percent. Your advantage is the universal applicability. They are suitable both for mineral substrates and for the reworking of old dispersion coatings.

Histolith Sol-Silicate contains lithium water glass as an additional binder component. In the silicification of lithium water glass, in contrast to the potassium water glass otherwise used in silicate paints, no potash efflorescence can occur, which occasionally gives rise to complaints.

Source: Caparol